diff --git a/Observable.js b/Observable.js
index 03545cd..673a7a5 100644
--- a/Observable.js
+++ b/Observable.js
@@ -11,12 +11,15 @@ class ObserverList {
   }
   add(observer) {
     // todo add observer to list
+    this.observerList.push(observer);
   }
   remove(observer) {
     // todo remove observer from list
+    this.observerList = this.observerList.filter(ob => ob != observer);
   }
   count() {
     // return observer list size
+    return this.observerList.length;
   }
 }
 
@@ -26,12 +29,15 @@ class Subject {
   }
   addObserver(observer) {
     // todo add observer
+    this.observers.add(observer);
   }
   removeObserver(observer) {
     // todo remove observer
+    this.observers.remove(observer);
   }
   notify(...args) {
     // todo notify
+    this.observers.observerList.map(ob => ob.update.call(ob, ...args))
   }
 }
 
diff --git a/PubSub.js b/PubSub.js
index 0c7999e..e889053 100644
--- a/PubSub.js
+++ b/PubSub.js
@@ -13,14 +13,23 @@ module.exports = class PubSub {
 
   subscribe(type, fn) {
     // todo subscribe
+    if (!this.subscribers[type]) {
+      this.subscribers[type] = [fn];
+    } else {
+      this.subscribers[type] = this.subscribers[type].concat(fn);
+    }
   }
 
   unsubscribe(type, fn) {
     // todo unsubscribe
+    if (!this.subscribers[type]) return;
+    this.subscribers[type] = this.subscribers[type].filter(func => func != fn);
   }
 
   publish(type, ...args) {
     // todo publish
+    if (!this.subscribers[type]) return;
+    this.subscribers[type].map(func => func.call(this, ...args));
   }
 
 }